1. Field of the Invention
The invention pertains to a screw unit for the adjustable and lockable spanning of distances between structural components, brackets, and for the adjustment of assemblies, etc.
2. Description of the Related Art
A screw unit described in EP 0,543,046 B1 consists of a threaded pin with adjusting surfaces and a central bore; a nut, which is designed as a support sleeve with an internal thread, is screwed onto the pin. Certain areas of the sleeve are provided with adjusting surfaces. The threaded pin can be screwed into the nut until it is more or less flush. The end of the support sleeve facing an adjusting collar on the threaded pin is provided with an inward-projecting, ring-shaped collar with the internal thread. A stop element is provided on the free end of the threaded pin to prevent it from being completely unscrewed. A screw unit such as this can be used both to keep a certain distance between two structural components and to level them; it can also be adjusted and re-adjusted over a considerable distance without the danger of the threaded pin being screwed all the way out of the support sleeve. The threads also overlap sufficiently to ensure that the support forces can be reliably absorbed. To connect the components, brackets, etc., mounted a certain distance away from each other, a fastening screw passes all the way through the screw unit. The centers of the mounting holes in the components must be aligned with each other, but this is not ensured in many cases because of manufacturing tolerances, which means either that deformations will occur or that the parts must be remachined.